Interpretive Summary: The oriental fruit fly is a serious pest of agriculture. Pesticides are still one of the main methods for their control. However, increasingly, pesticide use and activity is being studied in order to minimize the amount of pesticides used or to better understand how these pesticides work on the insect. In this study, we looked at different amounts of the chemical Cyazypr to determine it's toxicity and possible mode of action against the oriental fruit fly. The results suggest that this chemical can affect various metabolic processes in this fly. This can result in behavioral differences and other sublethal effects.

Technical Abstract:
The oriental fruit fly, Bactrocera dorsalis (Hendel) is one of the most important and damaging fruit pests in the world. Studies were conducted with a novel anthranilic diamide insecticide (i.e. DuPontTM CyazypyrTM) cyantraniliprole to determine its lethal and sublethal effects on B. dorsalis. An ingestion toxicity bioassay showed that the compound was active against B. dorsalis, and the 72h feeding LC50 was 3.221 µg/g in adult diet for a susceptible strain. Sublethal does of cyantraniliprole (3.271 µg/g adult diet and 1.302 µg/g adult diet) could induce a non-expected hormesis effect on B. dorsalis. The mating competitiveness of both males and females of B. dorsalis treated with 3.271 µg/g adult diet of cyantraniliprole was significantly lower than the control. The lower dose (1.302 µg/g adult diet) of cyantraniliprole improved the mating durations of both mating pairs in treated groups and also the mating competitiveness of the treated males when compared with the higher doses. On the fifth day, female receptivity was significantly reduced compared with control. The number of egg laid and subsequent egg hatch were not affected by cyantraniliprole, except the fecundity at the lower dose. These results indicate that cyantraniliprole is effective against B. dorsalis, with a hormesis sublethal effect on the adult’s mating performance.